Problem: Reduce to simplest form. $-\dfrac{5}{9}+\left(-\dfrac{7}{12}\right)=$
Solution: $=-{\dfrac{5\cdot 4}{9\cdot4}} - {\dfrac{7\cdot3}{12\cdot3}}$ $=-{\dfrac{20}{36}}-{\dfrac{21}{36}}$ $=-\dfrac{41}{36}$ or $-1\dfrac{5}{36}$